Liquid crystal compound and process for production thereof, liquid crystal composition, and liquid crystal electrooptical element

ABSTRACT

Disclosed is a liquid crystal composition suitable for producing a liquid crystal electrooptical element which can be driven at a low voltage in a wide temperature range and has high display quality. Also disclosed is a liquid crystal electrooptical element produced by using the liquid crystal composition. Further disclosed is a liquid crystal compound represented by the formula [R 1 -(A 1 ) a -Z 1 -(A 2 ) b -Z 2 -(A 7 ) e -Z 5 -A 3 -CF═CFCF 2 O-A 4 -Z 3 -(A 5 ) c -Z 4 -(A 6 ) d -R 2 ]. In the formula, R 1  and R 2  independently represent a hydrogen atom, a halogen atom, —CN, —NCS, —SF 5 , or an alkyl group containing 1 to 18 carbon atoms; A 1 , A 2 , A 3 , A 4 , A 5 , A 6  and A 7  independently represent trans-1,4-cyclohexylene group, 1,4-cyclohexenylene group, 1,3-cyclobutylene group, 1,2-cyclopropylene group, naphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, or 1,4-phenylene group; Z 1 , Z 2 , Z 3 , Z 4 , and Z 5  independently represent a single bond, an alkylene group containing 1 to 4 carbon atoms; and a, b, c, d, and e independently represent 0 or 1 with the proviso that 0≦a+b+c+d+e≦3.

This application is a continuation of International Application No.PCT/JP2009/068322, filed on Oct. 26, 2009. This application also claimspriority to Japanese application No. 2008-279647, filed on Oct. 30,2008. Both of those applications are incorporated herein by reference.

TECHNICAL FIELD

This invention relates to a liquid crystal compound and its productionmethod. This invention also relates to a liquid crystal composition anda liquid crystal display element containing the liquid crystal compound.

BACKGROUND ART

Liquid crystal elements are used in mobile equipment such as mobilephone and PDA, display for OA equipment such as copying machine and PCmonitor, display for home appliance such as TV, as well as clock,calculator, measuring instrument, automobile instruments, camera, andthe like, and the liquid crystal elements are required to fulfillvarious performances including wide operating temperature range, lowoperating voltage, high-speed responsivity, and chemical stability.

A material exhibiting liquid crystal phase is used in these liquidcrystal elements. Until now, however, the required performances are notrealized by one single compound fulfilling all required properties butby way of a liquid crystal composition prepared by mixing two or moreliquid crystal compounds or non-liquid crystal compounds each exhibitingone or more excellent properties.

Of the many properties required for the liquid crystal compound used inthe liquid crystal composition in the field of the liquid crystalelement, it is an important issue to provide a liquid crystal compoundor a liquid crystal composition which has excellent compatibility withother liquid crystal material or non-liquid crystal material andimproved chemical stability, and which also enables operation of theliquid crystal element at a low voltage with a high-speed responsivityin a wide operating temperature range when used for a liquid crystalelement.

As a measure for solving such problem, a compound containing CF═CFlinkage group and a compound containing CF₂O linkage group have beenused (Patent Literatures 1 and 2).

However, the compound containing CF═CF linkage group has the problem ofthe lack of photostability while the compound containing CF₂O linkagegroup has the problem that the CF₂O is decomposed when the compound hasparticular structures.

CITATIONS

-   Patent Literature 1: JP 03-041037 A-   Patent Literature 2: JP 05-112778 A

SUMMARY OF THE INVENTION

An object of the present invention is to provide a liquid crystalcompound which has a high positive Δ∈, an excellent compatibility withother liquid crystal material or non-liquid crystal material, and animproved chemical stability, and which also enables operation of theliquid crystal element at a low voltage with a high-speed responsivityin a wide operating temperature range when used in the liquid crystalelement. Another object of the present invention is to provide itsproduction method.

A further object of the present invention is to provide a liquid crystalcomposition containing such liquid crystal compound which is welladapted for use in producing a liquid crystal electrooptical elementwhich can be operated at a low voltage in a wide operating temperaturerange with high display quality. A still further object of the presentinvention is to provide a liquid crystal electrooptical element producedby using such liquid crystal composition.

In view of the situation as described above, the inventors of thepresent invention conducted an intensive study, and found that acompound having a particular structure having CF═CFCF₂O linkage group isa compound useful for realizing various performances such as wideoperating temperature range, low operating voltage, high-speedresponsivity, chemical stability, and the like required for the liquidcrystal electrooptical element when such compound is incorporated in theliquid crystal composition and the liquid crystal composition is used inthe liquid crystal electrooptical element.

Accordingly, the present invention provides a liquid crystal compoundrepresented by the following formula (1):R¹-(A¹)_(a)-Z¹-(A²)_(b)-Z²-(A⁷)_(e)-Z⁵-A³-CF═CFCF₂O-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²  (1)

The symbols of the formula (1) indicate following meaning.

-   R¹ and R²: They independently represent hydrogen atom, a halogen    atom, —CN, —NCS, —SF₅, or an alkyl group containing 1 to 18 carbon    atoms. At least one hydrogen atom in the group is optionally    substituted with fluorine atom. At least one —CH₂— in the group is    optionally substituted with ethereal oxygen atom or thioethereal    sulfur atom. At least one —CH₂CH₂— in the group is optionally    substituted with —CH═CH— or —C≡C—.-   A¹, A², A³, A⁴, A⁵, A⁶ and A⁷: They independently represent    trans-1,4-cyclohexylene group, 1,4-cyclohexenylene group,    1,3-cyclobutylene group, 1,2-cyclopropylene group,    naphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl    group, decahydronaphthalene-2,6-diyl group, or 1,4-phenylene group.    At least one hydrogen atom in the group is optionally substituted    with a halogen atom. One or two ═CH— in the group is optionally    substituted with nitrogen atom. One or two —CH₂— in the group is    optionally substituted with ethereal oxygen atom or thioethereal    sulfur atom.-   Z¹, Z², Z³, Z⁴, and Z⁵: They independently represent single bond, an    alkylene group containing 1 to 4 carbon atoms. At least one hydrogen    atom in the group is optionally substituted with fluorine atom. At    least one —CH₂— in the group is optionally substituted with ethereal    oxygen atom or thioethereal sulfur atom. At least one —CH₂CH₂— in    the group is optionally substituted with —CH═CH— or —C≡C—. a, b, c,    d, and e: They independently represent 0 or 1 with the proviso that    0≦a+b+c+d+e≦3.

A preferred liquid crystal compound represented by the formula (1) isthe compound represented by the following formula (1-0):R¹-(A¹)_(a)-Z¹-(A²)_(b)-Z²-A³-CF═CFCF₂O-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²  (1-0)

The symbols of the formula (1-0) indicate following meaning.

In the compound (1-0), R¹, R², Z¹, Z², Z³, Z⁴, a, b and C are as definedabove, with the proviso that 0≦a+b+c+d≦3.

A preferred liquid crystal compound represented by the formula (1-0) isthe compound represented by the following formula (1-1):formula (1-1):R¹¹-(A¹¹)_(a)-Z¹¹-(A²¹)_(b)-Z²¹-A³¹-CF═CFCF₂O-A⁴¹-Z³¹-(A⁵¹)_(c)-Z⁴¹-(A⁶¹)_(d)-R²¹  (1-1)

The symbols of the formula (1-1) indicate following meaning.

-   R¹¹ and R²¹: They independently represent hydrogen atom, fluorine    atom, —SF₅, or an alkyl group containing 1 to 18 carbon atoms. At    least one hydrogen atom in the group is optionally substituted with    fluorine atom. At least one —CH₂— in the group is optionally    substituted with ethereal oxygen atom or thioethereal sulfur atom.    At least one —CH₂CH₂— in the group is optionally substituted with    —CH═CH—.-   A¹¹, A²¹, A³¹, A⁴¹, A⁵¹, and A⁶¹: They independently represent    trans-1,4-cyclohexylene group or 1,4-phenylene group. At least one    hydrogen atom in the group is optionally substituted with a halogen    atom. One or two ═CH— in the group is optionally substituted with    nitrogen atom. One or two —CH₂— in the group is optionally    substituted with ethereal oxygen atom or thioethereal sulfur atom.-   Z¹¹, Z²¹, Z³¹, and Z⁴¹: They independently represent single bond, an    alkylene group containing 1 to 4 carbon atoms. At least one hydrogen    atom in the group is optionally substituted with fluorine atom. At    least one —CH₂— in the group is optionally substituted with ethereal    oxygen atom.

a, b, c, and d are as defined above.

A preferred liquid crystal compound represented by the formula (1-0) isthe compound represented by the following formula (1-2):R¹²-(A¹²)_(a)-Z¹²-(A²²)_(b)-Z²²-A³²-CF═CFCF₂O-A⁴²-Z³²-(A⁵²)_(c)-Z⁴²-(A⁶²)_(d)-R²²  (1-2)

The symbols of the formula (1-2) indicate following meaning.

-   R¹²: represents hydrogen atom or an alkyl group containing 1 to 10    carbon atoms, wherein at least one hydrogen atom in the group is    optionally substituted with fluorine atom, wherein at least one    —CH₂— in the group is optionally substituted with ethereal oxygen    atom,-   R²²: represents hydrogen atom, fluorine atom, —SF₅, or an alkyl    group containing 1 to 18 carbon atoms, wherein at least one hydrogen    atom in the group is optionally substituted with fluorine atom, and    at least one —CH₂— in the group is optionally substituted with    ethereal oxygen atom,-   A¹², A²², A³², A⁴², A⁵² and A⁶²: independently represent    trans-1,4-cyclohexylene group, 1,4-phenylene group, or 1,4-phenylene    group wherein one or two hydrogen atoms in the group is substituted    with fluorine atom,-   Z¹², Z²², Z³² and Z⁴²: independently represent single bond or an    alkylene group containing 1 to 4 carbon atoms, and

a, b, c, and d are as defined above.

A preferred method for producing the liquid crystal compound representedby the formula (1) comprises the step of reacting the compoundrepresented by the following formula (2):CF₂═CFCF₂O-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²  (2)with the compound represented by the following formula (3):R¹-(A¹)_(a)-Z¹-(A²)_(b)-Z²-(A⁷)_(e)-Z⁵-A³-M  (3).

The symbols of the formulae (2) and (3) are as defined above.

M of the formula (3) is a metal atom or a group containing a metal atom.

The present invention provides a liquid crystal composition containingthe liquid crystal compound represented by the formula (1).

The present invention provides a liquid crystal electrooptical elementhaving the liquid crystal composition introduced between two substrateseach having an electrode provided thereon.

The liquid crystal compound represented by the formula (1) of thepresent invention has high compatibility with other liquid crystalmaterial or non-liquid crystal material as well as high chemicalstability. The compound of the present invention can be used inpreparing a liquid crystal composition which fulfills variousperformances such as wide operating temperature range, low operatingvoltage, high-speed responsivity, chemical stability, and the likerequired for the liquid crystal element by adequately selecting thecyclic group, the substituent, and the linkage group constituting thecompound. In addition, when this liquid crystal composition is used inthe liquid crystal electrooptical element, the element shows improvedhigh-speed responsivity in a wide temperature range and it can beoperated at a low voltage.

According to the production method of the present invention, a compoundhaving CF═CFCF₂O linkage group can be readily and efficiently producedin commercial scale in versatile and convenient manner.

DETAILED DESCRIPTION OF THE INVENTION

Next, the present invention is described in detail.

In the present invention, the liquid crystal compound represented by theformula (1) is referred to as the compound (1), and compoundsrepresented by other formulae are also referred in the same manner.

In the present invention, in the formulae (1) and (3), the position nearR¹ is always referred to as the position 4 unless otherwise noted, andin the formula (2), the position near R² is always referred to as theposition 1 unless otherwise noted.

Also, in the present invention, “liquid crystal electrooptical element”is not limited to display elements but also includes various functionalelements using the electric or optical properties of the liquid crystal,for example, liquid crystal display element, and elements used inapplication such as smart window, optical shutter, polarizationconverting element, and varifocal lens.

In the compound (1) having the CF═CFCF₂O linkage group of the presentinvention, R¹ and R² are as defined above.

It is to be noted that the substitution of the hydrogen atom with thefluorine atom, the substitution of the —CH₂— with the ethereal oxygenatom or the thioethereal sulfur atom, and the substitution of the—CH₂CH₂— with the —CH═CH— or the —C≡C— may take place at once at thesame alkyl group.

The alkyl group substituted with at least one member selected fromfluorine atom, ethereal oxygen atom, and thioethereal sulfur atom ishereinafter referred to as the “substituted alkyl group”.

The alkenyl group which is the alkyl group substituted with “—CH═CH—”further substituted with at least one member selected from fluorineatom, ethereal oxygen atom, and thioethereal sulfur atom is hereinafterreferred to as the “substituted alkenyl group”.

Exemplary substituted alkyl groups include alkoxy group, alkoxyalkylgroup, alkylthio group, alkylthioalkyl group, fluoroalkyl group, andfluoroalkoxy group.

Exemplary substituted alkenyl groups include alkenyloxy group,alkenyloxyalkyl group, alkenylthio group, alkenylthioalkyl group,fluoroalkenyl group, and fluoroalkenyloxy group.

R¹ and R² are preferably hydrogen atom, a halogen atom, —CN, —NCS, —SF₅,an alkyl group, an alkoxy group, an alkoxyalkyl group, an alkylthiogroup, an alkylthioalkyl group, an alkenyl group, an alkenyloxy group,an alkenylthio group, a fluoroalkyl group, a fluoroalkoxy group, afluoroalkoxyalkyl group, a fluoroalkenyl group, or a fluoroalkenylthiogroup.

Exemplary alkyl groups include methyl group, ethyl group, propyl group,isopropyl group, butyl group, pentyl group, hexyl group, heptyl group,octyl group, nonyl group, and decyl group.

Exemplary alkoxy groups include methoxy group, ethoxy group, propoxygroup, butoxy group, pentoxy group, heptyloxy group, and octyloxy group.

Exemplary alkoxyalkyl groups include methoxymethyl group, ethoxymethylgroup, propoxymethyl group, propoxyethyl group, methoxypropyl group,ethoxypropyl group, and propoxypropyl group.

Exemplary alkylthio groups include methylthio group, ethylthio group,propylthio group, butylthio group, pentylthio group, hexylthio group,hepthylthio group, and octylthio group.

Exemplary alkylthioalkyl groups include methylthiomethyl group,ethylthiomethyl group, propylthiomethyl group, butylthiomethyl group,methylthioethyl group, ethylthioethyl group, propylthioethyl group,methylthiopropyl group, ethylthiopropyl group, and propylthiopropylgroup.

Exemplary alkenyl groups include vinyl group, 1-propenyl group,1-butenyl group, 1-pentenyl group, 3-butenyl group, and 3-pentenylgroup.

Exemplary alkenyloxy groups include allyloxy group.

Exemplary fluoroalkyl groups include trifluoromethyl group, fluoromethylgroup, 2-fluoroethyl group, difluoromethyl group, 2,2,2-trifluoroethylgroup, 1,1,2,2-tetra fluoroethyl group, 2-fluoroethyl group,3-fluoropropyl group, 4-fluorobutyl group, and 5-fluoropentyl group.

Exemplary fluoroalkoxy groups include fluoromethoxy group,trifluoromethoxy group, difluoromethoxy group, pentafluoroethoxy group,1,1,2,2-tetrafluoroethoxy group, heptafluoropropoxy group, and1,1,2,3,3,3-hexafluoropropoxy group.

Exemplary fluoroalkoxyalkyl groups include trifluoromethoxymethyl group.

Exemplary fluoroalkenyl groups include 2-fluoroethenyl group,2,2-difluoroethenyl group, 1,2,2-trifluoroethenyl group,3-fluoro-1-butenyl group, and 4-fluoro-1-butenyl group.

Exemplary fluoroalkenylthio groups include trifluoromethylthio group,difluoromethylthio group, 1,1,2,2-tetrafluoroethylthio group, and2,2,2-trifluoroethylthio group.

R¹ and R² are preferably hydrogen atom, fluorine atom, —SF₅, an alkylgroup containing 1 to 18 carbon atoms, an alkenyl group containing 2 to18 carbon atoms, a substituted alkyl group containing 1 to 18 carbonatoms, or a substituted alkenyl group containing 2 to 18 carbon atoms inview of the reactivity and the reduced side reaction.

R¹ is most preferably hydrogen atom, an alkyl group containing 10 carbonatoms, or a substituted alkyl group containing 10 carbon atoms.

R² is most preferably fluorine atom, —SF₅, hydrogen atom, an alkyl groupcontaining 10 carbon atoms, or a substituted alkyl group containing 10carbon atoms.

In the compound (1), A¹, A², A³, A⁴, A⁵, A⁶, and A⁷ are as definedabove.

It is to be noted that the substitution of the hydrogen atom with thehalogen atom, the substitution of the ═CH— with the nitrogen atom, andthe substitution of the —CH₂— with the ethereal oxygen atom or thethioethereal sulfur atom may take place at once at the same group. Thehalogen atom that may substitute the hydrogen atom in the group ispreferably chlorine atom or fluorine atom.

When A¹, A², A³, A⁴, A⁵, A⁶, and A⁷ are 1,4-phenylene group, the numberof halogen atom substituted is 1 to 4, and preferably 1 or 2. When A¹,A², A³, A⁴, A⁵, A⁶, and A⁷ are trans-1,4-cyclohexylene group, the numberof halogen atom substituted is 1 to 4. The halogen atom may also bebonded to the carbon atom at position 1 or 4 of the cyclohexylene group.

Examples of the 1,4-phenylene group having 1 or 2 ═CH— substituted withnitrogen atom include 2,5-pyrimidinylene group and 2,5-pyridinylenegroup.

Examples of the trans-1,4-cyclohexylene group having 1 or 2 —CH₂—substituted with ethereal oxygen atom or thioethereal sulfur atominclude 1,3-dioxane-2,5-diyl group and 1,3-dithian-2,5-diyl group.

The 1,4-phenylene group substituted with at least one member selectedfrom halogen atom and nitrogen atom is hereinafter referred to as the“substituted 1,4-phenylene group” and the 1,4-cyclohexylene groupsubstituted with at least one member selected from halogen atom,ethereal oxygen atom, and thioethereal sulfur atom is hereinafterreferred to as the “substituted trans-1, 4-cyclohexylene group”.

A¹, A², A³, A⁴, A⁵, A⁶, and A⁷ are preferably trans-1,4-cyclohexylenegroup, 1,4-phenylene group, substituted trans-1,4-cyclohexylene group,or substituted 1,4-phenylene group in view of the reactivity andavailability of the starting material.

Among these, the preferred are trans-1,4-cyclohexylene group,1,4-phenylene group, and 1,4-phenylene group having 1 or 2 hydrogenatoms substituted with fluorine atom.

In the compound (1), Z¹, Z², Z³, Z⁴, and Z⁵ are as defined above.

It is to be noted that the substitution of the hydrogen atom with thefluorine atom and the substitution of the —CH₂— with the ethereal oxygenatom or the thioethereal sulfur atom may take place at once at the samegroup.

Exemplary alkylene groups having at least one hydrogen atom in the groupsubstituted with fluorine atom include —CF₂CF₂—, —CF₂CH₂—, —CH₂CF₂—,—CHFCH₂—, —CH₂CHF—, —CF₂CHF—, and —CHFCF₂—.

Exemplary alkylene group having at least one —CH₂— in the groupsubstituted with ethereal oxygen atom or thioethereal sulfur atominclude —CH₂O—, —OCH₂—, —CH₂S—, and —SCH₂—.

Exemplary group having the hydrogen atom in the group substituted withthe fluorine atom and the —CH₂— in the group substituted with theethereal oxygen atom at once include —CF₂O— and —OCF₂—.

When the Z¹, Z², Z³, Z⁴, or Z⁵ is single bond, it means that the groupson both sides of the Z¹, Z², Z³, Z⁴, or Z⁵ are directly bonded to eachother. For example, when Z¹ is single bond and a and b are 1, A¹ and A²are directly bonded to each other, and when Z¹, Z², and Z⁵ are singlebond and a, b, and e are 0, R¹ and A³ are directly bonded to each other.

Z¹, Z², Z³, Z⁴, and Z⁵ are preferably single bond, an alkylene groupcontaining 1 to 4 carbon atoms, an alkylene group containing 1 to 4carbon atoms having at least one hydrogen atom substituted with fluorineatom, or an alkylene group containing 1 to 4 carbon atoms having atleast one —CH₂— substituted with ethereal oxygen atom, in view of theease of the synthesis and other reasons.

Among these, the most preferred is the single bond or the alkylene groupcontaining 1 to 4 carbon atoms.

In the compound (1) of the present invention, a, b, c, d, and e are asdefined above.

a, b, c, d, and e, however, may be adequately selected depending on theproperties required for the compound.

For example, when it is important that the compound (1) has lowviscosity or the compound (1) has high compatibility with other liquidcrystal material or non-liquid crystal material, it is preferable that0≦a+b+c+d+e≦1. On the other hand, when the high liquid crystaltemperature range of the compound (1) is important, it is preferablethat 1≦a+b+c+d+e≦3.

In view of increasing As of the compound (1), it is believed that the“-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²” on the oxygen side of the CF═CF—CF₂O ispreferably an electron-withdrawing group. The electron-withdrawingproperty of this “-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²” means that, in thecompound (1), “-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²” has anelectron-withdrawing property higher than that of the“-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²” wherein c=d=0, R² in the “-A⁴-R²” ishydrogen atom, and A⁴ is unsubstituted phenylene group or cyclohexylenegroup.

The “-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²” will be an electron withdrawinggroup when each group is as follows:

R² is fluorine atom, —OCF₃, —OCF₂H, —CN, —NCS, or —SF₅, A⁴, A⁵, and A⁶are independently 1,4-phenylene group, 2-fluoro-1,4-phenylene group, or2,6-difluoro-1,4-phenylene group,

Z³ and Z⁴ are single bond, and

c and d are independently 0 or 1.

In the conventional compound containing CF₂O linkage group, there wasthe risk that the unstable CF₂O linkage group would convert into COOwhen the carbon side of the CF₂O is substituted with 1,4-phenylene groupunless the 1,4-phenylene group is substituted with fluorine atom.

In addition, the compound containing the CF═CF linkage group sufferedfrom the problem that cis-trans isomerization is likely to take place byultraviolet or visible light when the CF═CF linkage group is substitutedwith 1,4-phenylene group.

In contrast, the compound having the CF═CFCF₂O linkage group of thepresent invention has a characteristic feature that, even if thislinkage group is substituted with 1,4-phenylene group which is notsubstituted with fluorine atom, it is substantially free ofdecomposition or isomerization of the linkage group, and therefore, thecompound has markedly improved stability.

This in turn means that the compound having the CF═CFCF₂O linkage groupof the present invention has the feature that the compound can be stablyproduced even if the structure of the cyclic group at both ends of thelinkage group is not limited to the fluorine-substituted 1,4-phenylenegroup or the like.

The compound (1) of the present invention is preferably compound (1-0):R¹-(A¹)_(a)-Z¹-(A²)_(b)-Z²-A³-CF═CFCF₂O-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²  (1-0)wherein notations in the formula are as defined above.

The compound (1-0) of the present invention is preferably the compound(1-1):R¹¹-(A¹¹)_(a)-Z¹¹-(A²)_(b)-Z²¹-A³¹-CF═CFCF₂O-A⁴¹-Z³¹-(A⁵¹)_(c)-Z⁴¹-(A⁶¹)_(d)-R²¹  (1-1)wherein notations in the formula are as defined above.

The compound (1-1) of the present invention is preferably the compound(1-2):R¹²-(A¹²)_(a)-Z¹²-(A²²)_(b)-Z²²-A³²-CF═CFCF₂O-A⁴²-Z³²-(A⁵²)_(c)-Z⁴²-(A⁶²)_(d)-R22  (1-2)wherein notations in the formula are as defined above.

The method for producing the compound (1) of the present inventionpreferably includes the step of reacting the compound (2) with thecompound (3).

In the compound (2) and compound (3), R¹, R², A ¹, A², A³, A⁴, A⁵, A⁶,A⁷, Z¹, Z², Z³, Z⁴, Z⁵, a, b, c, d, and e and preferable embodimentsthereof are as described above for the compound (1).

In compound (3), M represents a metal atom or a group containing a metalatom.

The compound (2) which is the starting material of the present inventionmay be prepared by the process described, for example, in WO2004-058676.

The compound (3) can be easily obtained by using a commerciallyavailable product, by the production described in books on organicsynthesis such as Shin Jikken Kagaku Koza[New Lectures on ExperimentalChemistry] (Maruzen Company, Limited), or by the method described inarticles such as J. Org. Chem., (2001), 66, 4333-4339 or J. Org. Chem.2008, 73, 522-528.

It is to be noted that the compound (3) may be reacted with the compound(2) after isolation of the compound (3), or alternatively, the compound(3) may be reacted continuously with the compound (2) without isolatingthe compound (3).

M is a metal atom or a group containing a metal atom. M is notparticularly limited as long as it undergoes addition and leavingreaction with the perfluoroallyloxy group of the compound (2), and thepreferred are MgI, MgBr, MgCl, and Li.

The compound (3) is preferably used at an amount of 0.9 to 2.0 moles,and more preferably at 1 to 1.5 moles per mole of the compound (2).

The production method of the present invention is preferably conductedin a solvent. Exemplary solvents include aromatic hydrocarbon solventssuch as benzene, toluene, xylene, and ethylbenzene; aliphatichydrocarbon solvents such as pentane, hexane, heptane, and octane; ethersolvents such as tetrahydrofuran, diethyl ether, diisopropyl ether,dibutyl ether, t-butylmethyl ether, and dimethoxyethane; petroleumethers; and adequate mixtures thereof. Among these, the preferred areether solvents such as diethylether and t-butylmethyl ether; and mixedsolvent of an ether solvent and an aliphatic hydrocarbon solvent.

The solvent is preferably used at an amount of 0.1 to 100 times, andmore preferably at 0.5 to 20 times more than the molar amount of thecompound (2). For example, when the compound (2) is used at 1 mmol, thesolvent is preferably used at 0.1 to 100 ml, and more preferably at 0.5to 20 ml.

The reaction is preferably conducted at −70 to 50° C., and morepreferably at −10 to 30° C.

The reaction is preferably conducted for a period of 0.1 to 24 hours,and more preferably 0.1 to 3 hours.

The production method of the present invention is preferably the one inwhich the compound (2) is the following compound (2-0):CF₂═CFCF₂O-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²  (2-0)the compound (3) the following compound (3-0):R¹-(A¹)_(a)-Z¹-(A²)_(b)-Z²-A³-M   (3-0), andthe compound (1) is the compound (1-0) as described above, whereinnotations in the formula are as defined above.

The production method of the present invention is more preferably theone in which the compound (2-0) is the following compound (2-1):CF₂═CFCF₂O-A⁴¹-Z³¹-(A⁵¹)_(c)-Z⁴¹-(A⁶¹)_(d)-R²¹  (2-1)the compound (3-0) the following compound (3-1):R¹¹-(A¹¹)_(a)-Z¹¹-(A²¹)_(b)-Z²¹-(A³¹)-M   (3-1), andthe compound (1-0) is the compound (1-1) as described above, whereinnotations in the formula are as defined above.

The production method of the present invention is most preferably theone in which the compound (2-0) is the following compound (2-2):CF₂═CFCF₂O-A⁴²-Z³²-(A⁵²)_(c)-Z⁴²-(A⁶²)_(d)-R²²  (2-2),the compound (3-0) is the following compound (3-2):R¹²-(A¹²)_(a)-Z¹²-(A²²)_(b)-Z²²-(A³¹)-M  (3-2), andthe compound (1-0) is the compound (1-2) as described above, whereinnotations in the formula are as defined above.

The present invention also provides a liquid crystal compositioncontaining the compound (1) as described above. This liquid crystalcomposition comprises a mixture of the compound (1) of the presentinvention with additional liquid crystal compound or non-liquid crystalcompound (which is generally referred to as “additional compound”).[0047]

Content of the compound (1) in the liquid crystal composition of thepresent invention may be adequately determined depending on theapplication, purpose of the use, types of other compounds, and the like.However, the compound (1) is preferably used at an amount of 0.5 to 50%by weight, and more preferably, at 2 to 20% by weight in relation to theentire amount of the liquid crystal composition. In addition, in thepresent invention, two or more type of the compound (1) may be includedin the liquid crystal composition, and in such a case, sum of the amountof the compounds (1) is preferably in the range of 0.5 to 80% by weight,and more preferably 2 to 50% by weight in relation to the entire amountof the liquid crystal composition.

Examples of the additional compound used by mixing with the compound (1)include a component for adjusting the level of refractive anisotropy, acomponent for reducing viscosity, a component which shows liquidcrystallinity at low temperature, a component for improving otherdielectric anisotropy, a component for imparting cholesteric property, acomponent exhibiting dichroism, a component for impartingelectroconductive property, and other additives. These may be adequatelyselected depending on the application, performance required, and thelike. However, those generally preferred are those comprising a maincomponent which is a liquid crystal compound or a compound having astructure similar to the liquid crystal compound and other additionalcomponents which have been added as required.

In the liquid crystal composition of the present invention, examples ofthe additional compound include the compounds represented by thefollowing formulae. In the following formulae, R³ and R⁴ which may bethe same or different represent groups such as alkyl group, alkenylgroup, alkynyl group, alkoxy group, halogen atom, or cyano group. Inaddition, Cy represents trans-1,4-cyclohexylene group, Ph represents1,4-phenylene group, and PhFF represents difluorophenylene group.R³-Cy-Cy-R⁴R³-Cy-Ph-R⁴R³-Cy-PhFF—CNR³-Ph-Ph-R⁴R³-Ph-C≡C-Ph-R⁴R³-Cy-COO-Ph-R⁴R³-Cy-COO-PhFF—CNR³-Ph-COO-Ph-R⁴R³-Ph-COO-PhFF—CNR³-Cy-CH═CH-Ph-R⁴R³-Ph-CH═CH-Ph-R⁴R³-Ph-CF═CF-Ph-R⁴R³-Cy-CF═CF-Ph-R⁴R³-Cy-CF═CF-Cy-R⁴R³-Cy-Ph-CF═CF-Ph-R⁴R³-Cy-Ph-CF═CF-Cy-R⁴R³-Ph-Cy-CF═CF-Cy-R⁴R³-Cy-Cy-CF═CF-Ph-R⁴R³-Ph-Ph-CF═CF-Ph-R⁴R³-Cy-CH₂CH₂-Ph-R⁴R³-Cy-Ph-CH₂CH₂-Ph-R⁴R³-Cy-Ph-CH₂CH₂-Cy-R⁴R³-Cy-Cy-CH₂CH₂-Ph-R⁴R³-Ph-CH₂CH₂-Ph-R⁴R³-Ph-Ph-CH₂CH₂-Ph-R⁴R³-Ph-Ph-CH₂CH₂-Cy-R⁴R³-Cy-Ph-Ph-R⁴R³-Cy-Ph-PhFF—CNR³-Cy-Ph-C≡C-Ph-R⁴R³-Cy-Ph-C≡C-PhFF—CNR³-Cy-Ph-C≡C-Ph-Cy-R⁴R³-Cy-CH₂CH₂-Ph-C≡C-Ph-R⁴R³-Cy-CH₂CH₂-Ph-C≡C-Ph-Cy-R⁴R³-Cy-Ph-Ph-Cy-R⁴R³-Ph-Ph-Ph-R⁴R³-Ph-Ph-C≡C-Ph-R⁴R³-Ph-CH₂CH₂-Ph-C≡C-Ph-R⁴R³-Ph-CH₂CH₂-Ph-C≡C-Ph-Cy-R⁴R³-Cy-COO-Ph-Ph-R⁴R³-Cy-COO-Ph-PhFF—CNR³-Cy-Ph-COO-Ph-R⁴R³-Cy-Ph-COO-PhFF—CNR³-Cy-COO-Ph-COO-Ph-RR³-Cy-COO-Ph-COO-PhFF—CNR³-Ph-COO-Ph-COO-Ph-R⁴R³-Ph-COO-Ph-OCO-Ph-R⁴R³-Ph-CF₂O-Ph-R⁴R³-Cy-CF₂ O-Ph-R⁴R³-Ph-CF₂ O-Cy-R⁴R³-Cy-Ph-CF₂ O-Ph-R⁴R³-Cy-Ph-CF₂ O-Cy-R⁴R³-Cy-Cy-CF₂ O-Ph-R⁴R³-Ph-Ph-CF₂ O-Ph-R⁴R³-Ph-Ph-CF₂ O-Cy-R⁴R³-Cy-Ph-CF₂ O-PhFF-R⁴R³-Cy-PhFF—CF₂ O-PhFF-R⁴R³-Ph-Ph-CF₂ O-PhFF-R⁴R³-Ph-PhFF—CF₂ O-PhFF-R⁴R³-Ph-CF₂CF₂-Ph-R⁴R³-Cy-CF₂CF₂-Ph-R⁴R³-Cy-CF₂CF₂-Cy-R⁴R³-Cy-Ph-CF₂CF₂-Ph-R⁴R³-Cy-Ph-CF₂CF₂-Cy-R⁴R³-Cy-Cy-CF₂CF₂-Ph-R⁴R³-Ph-Ph-CF₂CF₂-Ph-R⁴R³-Ph-Ph-CF₂CF₂-Cy-R⁴

The compounds as mentioned above are merely typical examples, otherexamples include these compounds having the hydrogen atom in its ringstructure or in its terminal group substituted with a halogen atom,cyano group, methyl group, or the like. Other examples include thosewherein the cyclohexane ring or the benzene ring is substituted withother six membered ring or five membered ring, for example, pyrimidinering or dioxane ring; and those wherein the linkage groups between therings are independently replaced with other divalent linkage bonds, forexample, —CH₂O—, —CH═CH—, —N═N—, —CH═N—, —COOCH₂—, —OCOCH₂—, or —COCH₂—.These compounds may also be selected depending on the desiredperformance.

The present invention also provides a liquid crystal electroopticalelement prepared by using the liquid crystal composition as describedabove as its constitutional material. For example, the present inventionprovides a liquid crystal electrooptical element having anelectrooptical element section prepared by sandwiching the liquidcrystal phase formed, for example, by introducing the liquid crystalcomposition of the present invention in a liquid crystal cell betweentwo substrates each equipped with an electrode. Exemplary liquid crystalelectrooptical elements include those driven by various modes includingtwisted nematic mode, guest-host mode, dynamic scattering mode, phasechange mode, DAP mode, dual frequency driven mode, and ferroelectricliquid crystal display mode.

A typical liquid crystal electrooptical element is twisted nematic (TN)liquid crystal display element. In producing the twisted nematic (TN)liquid crystal element, a substrate of plastic, glass, or other materialis overlaid with an undercoat layer of SiO₂, Al₂O₃, or the like or acolor filter layer, and a coating comprising In₂O₃—SnO₂ (ITO), SnO₂, orthe like is formed. An electrode of the required pattern is then formedby photolithography or the like, and after forming an optional overcoatlayer of polyimide, polyamide, SiO₂, Al₂O₃, or the like, orientationtreatment is conducted, and a sealing material is then printed. Afterarranging the substrates so that the electrode surface oppose to eachother, the periphery is sealed and the sealing material is cured toproduce an empty cell.

To this empty cell, the composition of the present invention isintroduced, and the inlet is closed by a sealant to constitute theliquid crystal cell. This liquid crystal cell is then overlaid asdesired with a polarizing plate, a color polarizing plate, a lightsource, a color filter, a semi-transparent reflective plate, areflective plate, a light guide plate, a UV cut filter, or the like, andafter printing necessary characters or figures, and the like, non-glaretreatment or other necessary treatment is conducted to thereby producethe liquid crystal electrooptical element.

It is to be noted that the above description is the basic constitutionand method for producing a liquid crystal electrooptical element, andvarious other constitution is also acceptable. Exemplary such otherconstitutions include a substrate prepared by using a dual-layerelectrode, a dual layer liquid crystal cell having two liquid crystallayers, a substrate prepared by using a reflective electrode, and anactive matrix element using an active matrix substrate formed with aTFT, MIM, or other active element.

In addition, the composition of the present invention may also be usedin a mode other than the TN liquid crystal electrooptical element asdescribed above, and exemplary such other modes include super-twistednematic (STN) liquid crystal electrooptical element using a greatertwist angle; guest-host (GH) liquid crystal electrooptical element usinga multichroic dye; in plane switching (IPS) liquid crystalelectrooptical element wherein the liquid crystal molecules are drivenin parallel direction to the substrate by applying transverse electricfield; VA liquid crystal electrooptical element wherein the liquidcrystal molecules are oriented in vertical direction to the substrate;and ferroelectric liquid crystal electrooptical element. The compositionof the present invention may also be used in a mode to be written byheat and not by electricity.

EXAMPLES

Next, the present invention is described in further detail by referringto the Examples which by no means limit the scope of the presentinvention.

Reference Example 1 Synthesis Compound (2A)

To a mixed solution of N,N-dimethylimidazolidinone (140 g),trifluorophenol (20 g), and triethylamine (93.6 g), perfluoroallylfluorosulfite (5.6 g) was added dropwise at a temperature of up to 10°C. After stirring at a temperature of up to 10° C. for 2 hours, ethylacetate (30 g) was added, and the mixture was washed with water (50 g).After removing the solvent by distillation, the residue was purified bysilica gel column chromatography to produce a compound (2A) (2.5 g).

Example 1 Synthesis Compound (1A)

Tetrahydrofuran (THF) (5 ml) and iodine (1 particle) were added tomagnesium (286 mg), and the mixture was fully stirred. To this mixture,a solution of 4-n-propyl(4-cyclohexyl)bromobenzene (2.71 g) in THF (5.42ml) was added dropwise at room temperature. After stirring at 30 to 40°C. for 4 hours, the reaction solution was cooled to a temperature of upto 10° C., and to this solution, a solution of compound (2A) (2.0 g) inTHF (2 ml) was added dropwise. The solution was stirred at roomtemperature, and after 15 hours, hexane (30 ml) was added, and themixture was washed with 1N aqueous hydrochloric acid solution, aqueoussolution of sodium bicarbonate, and water in this order. The solvent wasremoved by distillation, and the residue was purified by silica gelcolumn chromatography and recrystallization to obtain compound (1A)(0.68 g).

¹⁹F-NMR and GC-MS data of the resulting compound (1A) are as shownbelow.

¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −70.5 (dd,2F), −132.6 (m, 2F), −146.5 (dt, 1F), —163.3 (m, 1F), −167.6 (dt, 1F)

GC-MS M⁺=460

Compound (1A) had a clearing temperature (Tc) of 68.8° C. and arefractive anisotropy (Δn) of 0.116 when determined by extrapolationfrom liquid crystal composition ZLI-1565 manufactured by Merck & Co.,Inc.

Reference Example 2

Synthesis and purification was conducted by repeating the procedure ofReference Example 1 except that the trifluorophenol was replaced withdifluorophenol (17.6 g). Compound (2B) (27.3 g) was thereby obtained.

Example 2

Synthesis and purification was conducted by repeating the procedure ofExample 1 except that compound (2A) of Example 1 was replaced withcompound (2B) (1.87 g) obtained in Reference Example 2. Compound (1B)(0.47 g) was thereby obtained.

¹⁹F-NMR and GC-MS data of the resulting compound (2A) are as shownbelow.

¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −70.2 (dd,2F), −134.5 (m, 1F), −140.6 (m, 1F), −146.8 (dt, 1F), −167.2 (dt, 1F)

GC-MS M⁺=442

Tc and Δn were determined by repeating the procedure of Example 1.Compound (1B) had a Tc of 82.8° C., and a An of 0.135.

Example 3 Synthesis Compound (1C)

Tetrahydrofuran (THF) (400 ml) was added to4-n-propyl-3′-5′-difluorobiphenyl (50.1 g), and the mixture was fullystirred. The solution was cooled to −78° C., and a solution of n-butyllithium in n-hexane (1.6 mol/L) (135 ml) was added dropwise. Thesolution was stirred at −78° C., and after 1 hour, the compound (2A)(50.0 g) was added dropwise, and stirred at −78° C. After 2 hours, themixture was washed with 1N aqueous hydrochloric acid solution, aqueoussolution of sodium bicarbonate, and water in this order. The solvent wasremoved by distillation, and the residue was purified by silica gelcolumn chromatography and recrystallization to obtain compound (1C)(7.24 g).

¹⁹F-NMR and GC-MS data of the resulting compound (1C) are as shownbelow.

¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −71.3 (dd,2F), −109.0 (dd, 2F), −132.4 (m, 2F), −135.6 (m, 1F), −159.3 (m, 1F),−162.8 (m, 1F)

GC-MS M⁺=490

Compound (1C) had a clearing temperature (Tc) of −3.9° C. and arefractive anisotropy (An) of 0.136 when determined by extrapolationfrom liquid crystal composition ZLI-1565 manufactured by Merck & Co.,Inc.

Reference Example 3

Synthesis and purification was conducted by repeating the procedure ofReference Example 1 except that the trifluorophenol was replaced withmonofluorophenol (50.0 g). Compound (2C) (87.9 g) was thereby obtained.

Example 4 Synthesis Compound (10)

Tetrahydrofuran (THF) (450 ml) was added to lithium (3.87 g) and4,4′-di-tertiary butyl biphenyl (123.6 g), and the mixture was stirredat 15° C. for 1 hour. Next, hexane (450 ml) was added dropwise, and themixture was stirred at 15° C. for 2 hours. The reaction mixture wascooled to −65° C., and a solution of 4-(4′-n-pentylcyclohexyl)chlorocyclohexane (93.48 g) in THF (120 ml) was addeddropwise to this solution, and the mixture was stirred at −65° C. for 1hour. Next, a solution of the compound (2C) (42.2 g) in THF (60 ml) wasadded dropwise, and after stirring the solution overnight, the mixturewas washed with 1N aqueous hydrochloric acid solution, aqueous solutionof sodium bicarbonate, and water in this order. The solvent was removedby distillation, and the residue was purified by silica gel columnchromatography and recrystallization to obtain compound (1D) (4.42 g).

¹⁹F-NMR and GC-MS data of the resulting compound (1D) are as shownbelow.

¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −70.7 (dd,2F), −116.8 (d, 1F), −149.7 (dq, 1F), −172.7 (m, 1F)

GC-MS M⁺=458

Compound (1D) had a clearing temperature (Tc) of 93.0° C. and arefractive anisotropy (Δn) of 0.061 when determined by extrapolationfrom liquid crystal composition ZLI-1565 manufactured by Merck & Co.,Inc.

Example 5 Synthesis Compound (1E)

The procedure of Example 1 was repeated except that thep-(n-propyl-4-cyclohexyl)bromobenzene was replaced with p-n-propylbromobenzene (17.2 g) to obtain compound (1E) (16.7 g).

¹⁹F-NMR and GC-MS data of the resulting compound (1E) are as shownbelow.

¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −70.6 (dd,2F), −132.6 (m, 2F), −146.5 (dt, 1F), −163.3 (m, 1F), −167.6 (m, 1F)

GC-MS M⁺=378

Compound (1E) had a clearing temperature (Tc) of −67.8° C. and arefractive anisotropy (An) of 0.075 when determined by extrapolationfrom liquid crystal composition ZLI-1565 manufactured by Merck & Co.,Inc.

Example 6 Synthesis Compound (1F)

The procedure of Example 1 was repeated except that thep-(n-propyl-4-cyclohexyl)bromobenzene was replaced with4-n-propyl-4′-bromobiphenyl (11.9 g) to obtain compound (1F) (5.00 g).

¹⁹F-NMR and GC-MS data of the resulting compound (1F) are as shownbelow.

¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −70.6 (dd,2F), −132.6 (m, 2F), −147.0 (dt, 1F), −163.2 (m, 1F), −166.5 (m, 1F)

GC-MS M⁺=454

Compound (1F) had a clearing temperature (Tc) of 85.7° C. and arefractive anisotropy (Δn) of 0.1989 when determined by extrapolationfrom liquid crystal composition ZLI-1565 manufactured by Merck & Co.,Inc.

Example 7 Synthesis of Compound (1G)

The procedure of Example 1 was repeated except that thep-(n-propyl-4-cyclohexyl)bromobenzene was replaced with4-(4-n-propylcyclohexyl)-4′-bromobiphenyl (15.4 g) to obtain compound(1G) (5.00 g).

¹⁹F-NMR and GC-MS data of the resulting compound (1G) are as shownbelow.

¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −70.5 (dd,2F), −132.6 (m, 2F), −147.0 (dt, 1F), −163.2 (m, 1F), −166.6 (m, 1F)

GC-MS M⁺=536

Compound (1G) had a clearing temperature (Tc) of 192.1° C. and arefractive anisotropy (Δn) of 0.2209 when determined by extrapolationfrom liquid crystal composition ZLI-1565 manufactured by Merck & Co.,Inc.

Example 8 Synthesis Compound (1H)

A solution (86 ml) of isopropyl magnesium bromide (1.0 mol/L) in THF wasadded to THF (450 ml) which had been cooled to −78° C., and the mixturewas thoroughly stirred. A solution (105 ml) of n-butyl lithium (1.6mol/L) in n-hexane was added dropwise to this solution, and the mixturewas stirred at −78° C. After 1 hour, a solution (45 ml) of4-n-propyl-3′-fluoro-4′-bromobiphenyl (25.3 g) in THF was added, and themixture was stirred at −78° C. After 2 hours, compound (2A) (30.0 g) wasadded dropwise, and the mixture was stirred at −78° C. After 2 hours,the mixture was washed with 1N aqueous hydrochloric acid solution,aqueous solution of sodium bicarbonate, and water in this order. Thesolvent was removed by distillation, and the residue was purified bysilica gel column chromatography and recrystallization to obtaincompound (1H) (3.54 g).

¹⁹F-NMR and GC-MS data of the resulting compound (1H) are as shownbelow.

¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −71.1 (dd,2F), −110.2 (m, 1F), −132.5 (m, 2F), −136.7 (m, 1F), −162.7 (m, 1F),−163.1 (m, 1F)

GC-MS M⁺=472

Compound (1H) had a clearing temperature (Tc) of 32.6° C. and arefractive anisotropy (Δn) of 0.171 when determined by extrapolationfrom liquid crystal composition ZLI-1565 manufactured by Merck & Co.,Inc.

Example 9 Synthesis Compound (ii)

THF (1 ml) and iodine (1 particle) were added to magnesium (1.30 g), andthe mixture was thoroughly stirred. Next, bromoethane (0.90 g) was addeddropwise at 40° C., and the mixture was stirred. After 1 hour, asolution of 4-n-propyl(4-cyclohexyl)chlorocyclohexane (10.0 g) in THF(10.0 ml) was added dropwise at 40° C., and the mixture was stirred at30 to 40° C. for 3 hours. Compound (2A) (11.5 g), THF (20 ml), andcuprous bromide (1.2 g) were added to another reaction vessel, and themixture was cooled to −20° C., and to this mixture, the solution asdescribed above was added dropwise at -20° C., and the mixture wasstirred at room temperature. After 3 hours, the mixture was washed with1N aqueous hydrochloric acid solution, aqueous solution of sodiumbicarbonate, and water in this order. The solvent was removed bydistillation, and the residue was purified by silica gel columnchromatography and recrystallization to obtain compound (1I) (0.95 g).

¹⁹F-NMR and GC-MS data of the resulting compound (1I) are as shownbelow.

¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −71.4 (dd,2F), −132.8 (m, 2F), −148.6 (m, 1F), −163.4 (m, 1F), −173.3 (dt, 1F)

GC-MS M⁺=466

Compound (1A) had a clearing temperature (Tc) of 58.3° C. and arefractive anisotropy (Δn) of 0.0912 when determined by extrapolationfrom liquid crystal composition ZLI-1565 manufactured by Merck & Co.,Inc.

The following compounds may also be produced based on the description ofExamples 1 to 9 and the description of the section of “DESCRIPTION OFEMBODIMENTS”.

Examples of the two ring compound (those wherein all of a to e are 0)include:C₃H₇-Ph-CF═CFCF₂O-Ph-C₂H₅C₃H₇-Ph-CF═CFCF₂O-Ph-FC₃H₇-Ph-CF═CFCF₂O-Ph (2F)—FC₃H₇-Ph-CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Ph-CF═CFCF₂O-Ph (2F, 6F)—CNC₃H₇-Ph-CF═CFCF₂O-Ph (2F, 6F)—NCSC₃H₇-Ph-CF═CFCF₂O-Ph (2F, 6F)—SF₅C₃H₇-Ph-CF═CFCF₂O-Ph (2F)—OCF₃C₃H₇O-Ph-CF═CFCF₂O-Ph (2F)—OCF₃C₂H₅-Ph-CF═CFCF₂O-Ph (2F, 3F)—OCH₃C₅H₁₁-Ph-CF═CFCF₂O-Ph (2F, 6F)—OCF₂HCH₃CH═CH—C₂H₄-Ph-CF═CFCF₂O-Ph (2F, 6F)—FCH₃OCH₂-Ph-CF═CFCF₂O-Ph (2F, 3F)—FC₃H₇O-Ph (2F, 3F)—CF═CFCF₂O-Ph (2F, 3F)—FC₃H₇-Cy-CF═CFCF₂O-Ph-C₂H₅C₃H₇-Cy-CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-CF═CFCF₂O-Ph (2F, 6F)—CNC₃H₇O-Cy-CF═CFCF₂O-Ph (2F)—OCF₃C₂H₅-Cy-CF═CFCF₂O-Ph (2F, 3F)—OCH₃CH₃CH═CH—C₂H₄-Cy-CF═CFCF₂O-Ph (2F, 6F)—FCH₂═CH-Cy-CF═CFCF₂O-Ph (F, F)—FC₅H₁₁-Cy-CF═CFCF₂O-Ph (2F, 6F)—OCF₂H.

Examples of the three ring compound (those wherein 1 of a to e is 1 andother 4 are 0) include:C₃H₇-Cy-Ph-CF═CFCF₂O-Ph-C₂H₅C₃H₇-Cy-Ph-CF═CFCF₂O-Ph-FC₃H₇-Cy-Ph-CF═CFCF₂O-Ph (2F)—FC₃H₇-Cy-Ph-CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Ph-CF═CFCF₂O-Ph (2F, 6F)—CNC₂H₅-Cy-Ph-CF═CFCF₂O-Ph (2F, 6F)—NCSC₃H₇-Cy-Ph-CF═CFCF₂O-Ph (2F, 6F)—SF₅C₅H₁₁-Cy-Ph-CF═CFCF₂O-Ph (2F, 6F)—OCF₃C₃H₇-Cy-Ph-CF═CFCF₂O-Ph (2F, 3F)—OC₂H₅C₂H₅-Cy-Ph (2F, 3F)—CF═CFCF₂O-Ph (2F, 3F)—OC₂H₅C₃H₇-Cy-Ph (2F)—CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—OCF₃C₃H₇-Cy-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—CNC₂H₅-Ph-Ph-CF═CFCF₂O-Ph-FC₃H₇-Ph-Ph-CF═CFCF₂O-Ph (2F)—FC₃H₇-Ph-Ph-CF═CFCF₂O-Ph (2F, 6F)—FC₅H₁₁-Ph-Ph-CF═CFCF₂O-Ph (2F, 6F)—CNC₃H₇-Ph-Ph-CF═CFCF₂O-Ph (2F, 6F)—NCSC₃H₇-Ph-Ph-CF═CFCF₂O-Ph (2F, 6F)—SF₅C₃H₇-Ph-Ph-CF═CFCF₂O-Ph (2F, 6F)—OCF₃C₂H₅-Ph-Ph-CF═CFCF₂O-Ph (2F, 3F)—OC₂H₅C₃H₇-Ph-Ph (2F, 3F)—CF═CFCF₂O-Ph (2F, 3F)—OC₂H₅C₃H₇-Ph-Ph (2F)—CF═CFCF₂O-Ph (2F, 6F)—FC₅H₁₁-Ph-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Cy-CF═CFCF₂O-Ph-FCH₂═CH-Cy-Cy-CF═CFCF₂O-Ph (2F)—FC₃H₇-Cy-Cy-CF═CFCF₂O-Ph (2F)—OCF₃C₃H₇-Cy-Cy-CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Cy-CF═CFCF₂O-Ph (2F, 6F)—CNC₅H₁₁-Cy-Cy-CF═CFCF₂O-Ph (2F, 3F)—OC₂H₅C₅H₁₁-Cy-Cy-CF═CFCF₂O-Ph (2F, 6F)—OCF₂HC₂H₅-Ph-CF═CFCF₂O-Ph-Ph (2F)—FC₃H₇-Ph-CF═CFCF₂O-Ph-Ph (2F, 6F)—FC₃H₇-Ph-CF═CFCF₂O-Ph (2F, 6F)-Ph (2F, 6F)—FC₅H₁₁-Ph-CF═CFCF₂O-Ph (2F, 6F)-Ph (2F, 6F)—CNCH₃CH=CHC₂H₄-Ph-CF═CFCF₂O-Ph-Ph (2F)—FC₃H₇-Ph-CF═CFCF₂O-Ph-Ph (2F, 3F)—OCH₃C₃H₇-Ph (2F)—CF═CFCF₂O-Ph-Ph (2F, 6F)—FC₂H₅-Ph-CF═CFCF₂O-Ph-Cy-C₅H₁₁C₂H₅-Ph-CF═CFCF₂O-Ph (2F)-Cy-C₅H₁₁C₃H₇-Ph-CF═CFCF₂O-Ph (2F, 6F)-Cy-C₅H₁₁C₃H₇-Ph (2F, 3F)—CF═CFCF₂O-Ph-Cy-OC₂H₅C₂H₅-Cy-CF═CFCF₂O-Ph-Ph (2F)—FC₅H₁₁-Cy-CF═CFCF₂O-Ph-Ph (2F, 6F)—FC₃H₇-Cy-CF═CFCF₂O-Ph (2F, 6F)-Ph (2F)—OCF₃C₃H₇-Cy-CF═CFCF₂O-Ph (2F, 6F)-Ph (2F, 6F)—FC₅H₁₁-Cy-CF═CFCF₂O-Ph (2F, 6F)-Ph (2F, 6F)—CNC₃H₇-Cy-CF═CFCF₂O-Ph-Ph (2F, 3F)—OC₂H₅C₃H₇-Cy-C₂H₄-Ph-CF═CFCF₂O-Ph (2F)—FC₃H₇-Cy-C₂H₄-Ph (2F)—CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-C₂H₄-Ph (2F)—CF═CFCF₂O-Ph (2F, 6F)—OCF₃CH₃CH=CHC₂H₄-Cy-C₂H₄-Ph-CF═CFCF₂O-Ph (2F)—C₃H₇CH₂═CH-Cy-CH₂O-Ph-CF═CFCF₂O-Ph (2F)—FC₃H₇-Cy-CH₂O-Ph (2F, 3F)—CF═CFCF₂O-Ph (2F, 3F)—OC₂H₅.

Examples of the four ring compounds (those wherein 2 of a to e are 1 andother 3 are 0) include:C₃H₇-Ph-CF═CFCF₂O-Ph-Ph-Ph-C₂H₅C₃H₇-Ph-CF═CFCF₂O-Ph-Ph-Ph (2F, 6F)—FC₂H₅-Ph-CF═CFCF₂O-Ph-Ph (2F, 6F)-Ph (2F)—FC₅H₁₁-Ph-CF═CFCF₂O-Ph (2F)-Ph (2F)-Ph (2F)—CNC₅H₁₁-Ph-CF═CFCF₂O-Ph (2F)-Ph (2F, 6F)-Ph (2F)—OCF₃C₃H₇-Ph-CF═CFCF₂O-Ph (2F, 6F)-Ph (2F, 6F)-Ph (2F, 6F)—FC₂H₅-Ph (2F)—CF═CFCF₂O-Ph-Ph (2F, 6F)-Ph (2F)—CNC₂H₅-Ph (2F, 3F)—CF═CFCF₂O-Ph-Ph-Ph (2F)—FC₃H₇-Cy-CF═CFCF₂O-Ph-Ph-Ph-C₂H₅C₃H₇-Cy-CF═CFCF₂O-Ph-Ph-Ph (2F, 6F)—FC₂H₅-Cy-CF═CFCF₂O-Ph-Ph (2F, 3F)-Ph (2F, 3F)—OC₂H₅C₅H₁₁-Cy-CF═CFCF₂O-Ph (2F)-Ph (2F)-Ph (2F)—CNC₅H₁₁-Cy-CF═CFCF₂O-Ph (2F)-Ph (2F, 6F)-Ph (2F)—OCF₃C₃H₇-Cy-CF═CFCF₂O-Ph (2F, 6F)-Ph (2F, 6F)-Ph (2F, 6F)—FC₂H₅-Cy-CF═CFCF₂O-Ph-Ph (2F, 6F)-Ph (2F)—CNC₃H₇-Ph-CF═CFCF₂O-Ph (2F, 3F)-Ph (2F, 3F)-Cy-C₂H₅C₃H₇-Ph-CF═CFCF₂O-Ph (2F, 6F)-Ph (2F, 6F)-Cy-CH═CH₂C₃H₇-Ph (2F, 3F)—CF═CFCF₂O-Ph (2F, 3F)-Ph (2F, 3F)-Cy-CH₃C₃H₇-Ph-CF═CFCF₂O-Ph (2F, 3F)-Cy-Cy-C₂H₅C₃H₇-Ph-CF═CFCF₂O-Ph (2F, 6F)-Cy-Cy-OCH₃C₃H₇-Cy-Ph-CF═CFCF₂O-Ph-Ph-C₂H₅C₃H₇-Cy-Ph-CF═CFCF₂O-Ph (2F)-Ph (2F, 6F)—FC₅H₁₁-Cy-Ph-CF═CFCF₂O-Ph (2F, 6F)-Ph (2F, 6F)—OCF₃C₃H₇-Cy-Ph-CF═CFCF₂O-Ph-Cy-CH═CH₂C₅H₁₁-Cy-Ph-CF═CFCF₂O-Ph (2F, 3F)-Cy-C₂H₅C₃H₇-Cy-Ph (2F, 3F)—CF═CFCF₂O-Ph (2F, 3F)-Cy-C₂H₅C₃H₇-Cy-Cy-CF═CFCF₂O-Ph-Ph (2F)—FC₅H₁₁-Cy-Cy-CF═CFCF₂O-Ph (2F)-Ph (2F, 6F)—CNC₅H₁₁-Cy-Cy-CF═CFCF₂O-Ph (2F, 3F)-Ph (2F, 3F)—OC₂H₅C₅H₁₁-Cy-Cy-CF═CFCF₂O-Ph (2F)-Cy-C₃H₇C₃H₇-Cy-Cy-CF—CFCF₂O-Ph (2F, 6F)-Cy-OC₂H₅C₃H₇-Cy-Cy-CF═CFCF₂O-Ph (2F, 3F)-Cy-OCH₃C₃H₇-Ph-Ph-Ph-CF═CFCF₂O-Ph (2F)—OCF₃C₃H₇-Ph-Ph-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Ph-Ph (2F)-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—ONC₂H₅-Ph-Ph (2F, 6F)-Ph-CF═CFCF₂O-Ph (2F)—CNCH₃—CH═CH-C₂H₄-Ph-Ph-Ph-CF═CFCF₂O-Ph (2F)—FCH₂═CH-Cy-Cy-Cy-CF═CFCF₂O-Ph (2F)—OCF₃C₃H₇-Cy-Cy-Cy-CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Cy-Cy-CF═CFCF₂O-Ph (2F, 3F)—0C₂H₅C₂H₅O-Cy-Cy-Ph-CF═CFCF₂O-Ph (2F)—OCF₃C₃H₇-Cy-Cy-Ph-CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Cy-Ph (2F)—CF═CFCF₂O-Ph (2F, 6F)—CNC₃H₇-Cy-Cy-Ph-CF═CFCF₂O-Ph (2F, 3F)—OC₂H₅C₃H₇-Cy-Ph-Ph-CF═CFCF₂O-Ph (2F)—OCF₃C₃H₇-Cy-Ph-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Ph (2F)-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—ONC₂H₅-Cy-Ph (2F, 6F)-Ph-CF═CFCF₂O-Ph (2F)—CNCH₂═CH-Cy-Ph-Ph-CF═CFCF₂O-Ph (2F)—F.

Examples of the 5 ring compound (those wherein 3 of a to e are 1 andother 2 are 0) include:C₃H₇-Ph-Ph-Ph-Ph-CF═CFCF₂O-Ph (2F)—FC₃H₇-Ph-Ph-Ph-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Ph-Ph-Ph (2F)-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—ONC₂H₅-Ph-Ph-Ph (2F, 6F)-Ph-CF═CFCF₂O-Ph (2F)—CNCH₃—CH═CH-C₂H₄-Ph-Ph-Ph-Ph-CF═CFCF₂O-Ph (2F)—FCH₂═CH-Cy-Cy-Cy-Ph-CF═CFCF₂O-Ph (2F)—OCF₃C₃H₇-Cy-Cy-Cy-Ph-CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Cy-Cy-Ph-CF═CFCF₂O-Ph (2F, 3F)—OC₂H₅C₂H₅O-Cy-Cy-Ph-Ph-CF═CFCF₂O-Ph (2F)—OCF₃C₃H₇-Cy-Cy-Ph-Ph-CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Cy-Ph-Ph (2F)—CF═CFCF₂O-Ph (2F, 6F)—CNC₃H₇-Cy-Cy-Ph-Ph-CF═CFCF₂O-Ph (2F, 3F)—OC₂H₅C₃H₇-Cy-Ph-Ph-Ph-CF═CFCF₂O-Ph (2F)—OCF₃C₃H₇-Cy-Ph-Ph-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—FC₃H₇-Cy-Ph-Ph (2F)-Ph (2F, 6F)—CF═CFCF₂O-Ph (2F, 6F)—CNC₂H₅-Cy-Ph-Ph (2F, 6F)-Ph-CF═CFCF₂O-Ph (2F)—CNC₃H₇-Cy-Ph-Ph-Ph-CF═CFCF₂O-Ph (2F, 6F)—FCH₂═CH-Cy-Ph-Ph-Ph-CF═CFCF₂O-Ph (2F)—FC₃H₇-Ph-Ph-Ph-CF═CFCF₂O-Ph-Ph (2F)—FC₃H₇-Ph-Ph-Ph (2F, 6F)—CF═CFCF₂O-Ph-Ph (2F, 6F)—FC₃H₇-Ph-Ph (2F)-Ph (2F, 6F)—CF═CFCF₂O-Ph-Ph (2F, 6F)—CNC₂H₅-Ph-Ph (2F, 6F)-Ph-CF═CFCF₂O-Ph-Ph (2F)—CNCH₃—CH═CH-C₂H₄-Ph-Ph-Ph-CF═CFCF₂O-Ph-Ph (2F)—FCH₂=CH-Cy-Cy-Cy-CF═CFCF₂O-Ph-Ph (2F)—OCF₃C₃H₇-Cy-Cy-Cy-CF═CFCF₂O-Ph-Ph (2F, 6F)—FC₃H₇-Cy-Cy-Cy-CF═CFCF₂O-Ph-Ph (2F, 3F)—OC₂H₅C₂H₅O-Cy-Cy-Ph-CF═CFCF₂O-Ph-Ph (2F)—OCF₃C₃H₇-Cy-Cy-Ph-CF═CFCF₂O-Ph-Ph (2F, 6F)—FC₃H₇-Cy-Cy-Ph (2F)—CF═CFCF₂O-Ph-Ph (2F, 6F)—CNC₃H₇-Cy-Cy-Ph-CF═CFCF₂O-Ph-Ph (2F, 3F)—00₂H₅C₃H₇-Cy-Ph-Ph-CF═CFCF₂O-Ph-Ph (2F)—OCF₃C₃H₇-Cy-Ph-Ph (2F, 6F)—CF═CFCF₂O-Ph-Ph (2F, 6F)—FC₃H₇-Cy-Ph (2F)-Ph (2F, 6F)—CF═CFCF₂O-Ph-Ph (2F, 6F)—CNC₂H₅-Cy-Ph (2F, 6F)-Ph-CF═CFCF₂O-Ph-Ph (2F)—CNC₃H₇-Cy-Ph-Ph-CF═CFCF₂O-Ph-Ph (2F, 6F)—FCH₂=CH-Cy-Ph-Ph-CF═CFCF₂O-Ph-Ph (2F)—FC₃H₇-Ph-Ph-CF═CFCF₂O-Ph-Ph-Ph (2F)—FC₃H₇-Ph-Ph (2F, 6F)—CF═CFCF₂O-Ph-Ph-Ph (2F, 6F)—FC₃H₇-Ph (2F)-Ph (2F, 6F)—CF═CFCF₂O-Ph-Ph-Ph (2F, 6F)—CNC₂H₅-Ph (2F, 6F)-Ph-CF═CFCF₂O-Ph-Ph-Ph (2F)—CNCH₃—CH═CH-C₂H₄-Ph-Ph-CF═CFCF₂O-Ph-Ph-Ph (2F)—FCH₂═CH-Cy-Cy-CF═CFCF₂O-Ph-Cy-Ph (2F)—OCF₃C₃H₇-Cy-Cy-CF═CFCF₂O-Ph-Cy-Ph (2F, 6F)—FC₃H₇-Cy-Cy-CF═CFCF₂O-Ph-Cy-Ph (2F, 3F)—OC₂H₅C₂H₅O-Cy-Cy-CF═CFCF₂O-Ph-Ph-Ph (2F)—OCF₃C₃H₇-Cy-Cy-CF═CFCF₂O-Ph-Ph-Ph (2F, 6F)—FC₃H₇-Cy-Cy-CF═CFCF₂O-Ph-Ph (2F)-Ph (2F, 6F)—CNC₃H₇-Cy-Cy-CF═CFCF₂O-Ph-Ph-Ph (2F, 3F)—OC₂H₅C₃H₇-Cy-Ph-CF═CFCF₂O-Ph-Ph-Ph (2F)—OCF₃C₃H₇-Cy-Ph (2F, 6F)—CF═CFCF₂O-Ph-Ph-Ph (2F, 6F)—FC₃H₇-Cy-Ph (2F)—CF═CFCF₂O-Ph-Ph (2F, 6F)-Ph (2F, 6F)—CNC₂H₅-Cy-Ph (2F, 6F)—CF═CFCF₂O-Ph-Ph-Ph (2F)—CNC₃H₇-Cy-Ph-CF═CFCF₂O-Ph-Ph-Ph (2F, 6F)—FCH₂═CH-Cy-Ph-CF═CFCF₂O-Ph-Ph-Ph (2F)—F.

In the formulae as mentioned above, Cy representstrans-1,4-cyclohexylene group, Ph represents 1,4-phenylene group, Ph(2F) represents 2-fluoro-1,4-phenylene group, Ph (2F, 6F) represents2,6-difluoro-1,4-phenylene group, and Ph (2F, 3F) represents2,3-difluoro-1,4-phenylene group.

Comparative Example 1

The following compound (C1) was synthesized by usingp-(trans-4-n-propylcyclohexyl)iodobenzene for the iodobenzene derivativeof Example 3 in JP A 06-329566.

The resulting compound (C1) had the ¹⁹F-NMR as described below.

-   ¹⁹F-NMR (282.6 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm):-   −134.1 (m, 2F), −148.5 (d, 1F), −154.6 (d, 1F), −159.2 (m, 1F)

Comparative Example 2

The following compound (C1) was synthesized by usingp-(trans-4-n-propylcyclohexyl)iodobenzene for the iodobenzene derivativeof Example 2 in JP A 06-329566.

Observation of Compatibility

To a liquid crystal composition “ZLI-1565” manufactured by Merck & Co.,Inc., the compound (1A) of the present invention produced in Example 1and the compound (C1) produced in Comparative Example 1 were added at anamount shown in Table 1, below, and after the dissolution, the mixturewas stored at 0° C. After 72 hours, the state of the composition wasvisually observed.

The procedure as described above was repeated by using the compound (1B)produced in Example 2 and the compound (C2) produced in ComparativeExample 2. The results of the observation are shown in Table 2, below.

The case with no solid precipitation is indicated by “A”, and the casewith solid precipitation is indicated by “B”. The results are shown inthe Tables, below.

TABLE 1 Content 5% by 10% by 20% by 30% by weight weight weight weightCompound A A A A (1A) Compound A B B B (C1)

TABLE 2 Content 5% by 10% by 20% by 30% by weight weight weight weightCompound A A A A (1B) Compound A A A B (C2)Measurement of Bulk Viscosity

A liquid crystal composition comprising 80% by weight of the liquidcrystal composition “ZLI-1565” manufactured by Merck & Co., Inc. and 20%by weight of the compound (1A) of the present invention 20% by weight;and a liquid crystal composition comprising 90% by weight of the liquidcrystal composition “ZLI-1565” manufactured by Merck & Co., Inc. and 10%by weight of the compound (10) of the present invention were prepared.As a Comparative Example, a liquid crystal composition comprising 95% byweight of the liquid crystal composition “ZLI-1565” manufactured byMerck & Co., Inc. and 5% by weight of the compound (C1) was alsoprepared. These liquid crystal compositions were measured for theirviscosity at 25° C. and 0° C. using Model E viscometer, and theviscosity was calculated by extrapolation. The results are shown inTable 3.

For the compounds (1B) and (C2), a liquid crystal composition comprising80% by weight of the liquid crystal composition “ZLI-1565” manufacturedby Merck & Co., Inc. and 20% by weight of the compound (1B) or thecompound (C2) was prepared, and the viscosity was measured andcalculated by the same procedure. The results are shown in Table 4.

TABLE 3 25° C. 0° C. Compound 28.81 211.14 (1A) Compound 62.2 325.5 (1C)Compound 114.3 795.7 (C1)

TABLE 4 25° C. 0° C. Compound 20.6 85.1 (1B) Compound 22.6 92.4 (C2)Measurement of Dielectric Anisotropy (Δ∈)

Dielectric anisotropy was measured by using a liquid crystal compositionprepared by mixing the compound of the present invention with the liquidcrystal composition “ZLI-1565” manufactured by Merck & Co., Inc. Morespecifically, 20% by mole of the compound (1A), the compound (1B), orthe compound (C2) was mixed with 80% by mole of the “ZLI-1565”, while10% by mole of the compound (10), the compound (1E), the compound (1F),the compound (1H), or the compound (1I) was mixed with 90% by mole ofthe “ZLI-1565” 90% by mole. 5% by mole of the compound (C1) was mixedwith 95% by mole of the “ZLI-1565”.

The mixture was encapsulated in a glass cell comprising two glass plateplaced at an interval of 8 μm. A voltage of 100 mV was applied to thiscell to measure dielectric constant in minor axis direction (∈⊥), and avoltage of 88 V was applied to this cell to measure dielectric constantin major axis direction (∈∥). The dielectric anisotropy (Δ∈) of thecompound was determined by calculating Δ∈ of the composition by theformula: Δ∈=∈∥−∈⊥, and extrapolation.

The value of Δ∈ at 0.85 Tc is shown in Table 5, below. It is to be notedthat 0.85 Tc is the temperature (K) which is Tc (in terms of absolutetemperature (K)) of each liquid crystal composition multiplied by 0.85.

TABLE 5 Δε (0.85Tc) Compound 21.75 (1A) Compound 40.35 (1C) Compound18.5 (1E) Compound 21.52 (1F) Compound 27.3 (1H) Compound 14.8 (1I)Compound 11.24 (C1)

TABLE 6 Δε (0.85Tc) Compound 11.4 (1B) Compound 8.8 (C2)

As described above, the compound of the present invention was found tohave a high Δ∈ value, especially when compared with the comparativecompound having CF═CF structure. This means that use of the compound ofthe present invention for the liquid crystal composition enablesoperation at a low voltage of the liquid crystal electrooptical elementwhen the liquid crystal electrooptical element is prepared by using suchliquid crystal composition.

Measurement of Photostability

A composition comprising the liquid crystal composition ZLI-1565manufactured by Merck & Co., Inc. and 20% by weight of the compound (1A)was prepared. A composition comprising the liquid crystal compositionZLI-1565 manufactured by Merck & Co., Inc. and 10% by weight of thecompound (Cl) was also prepared by the same manner.

Each composition was encapsulated in a glass cell, and irradiated with axenon lamp.

Degree of the cis-isomerization and the decomposition of the sample wasdetermined by measuring the To at a time interval of 30 minutes. Themeasurement was conducted 3 times for each composition, and the resultsare shown in Table 6. For comparison purpose, a sample solely comprisingthe ZLI-1565 was also prepared for the measurement.

TABLE 7 Change in Tc Irradiation time (percentage (min.) of the 0 30 6090 change) Composition (1) 85.8 85.7 85.6 85.5 −0.3 (0.3%) solely (2)85.7 85.6 85.7 85.5 −0.2 (0.2%) comprising (3) 85.7 85.7 85.7 85.5 −0.2(0.2%) ZLI-1565 Composition (1) 82.4 82.3 82.2 82.0 −0.4 (0.5%)containing 20% (2) 82.4 82.3 82.2 82.0 −0.4 (0.5%) by weight of (3) 82.382.3 82.2 82.0 −0.3 (0.4%) Compound (1A) Composition (1) 91.2 88.3 85.983.7 −7.5 (8.2%) containing 10% (2) 91.3 88.3 85.8 83.6 −7.7 (8.4%) byweight of (3) 91.4 88.5 85.8 83.8 −7.6 (8.3%) Compound (C1)

To of the composition containing the compound (1A) exhibited nosubstantial change while Tc of the composition containing the compound(C1) showed great decrease. Since change of the Tc of the compositionincreases with the increase in the degree of the cis-isomerization andthe decomposition of the compound, the results indicates that thecompound (1A) of the present invention has an improved photostabilityover that of the compound (C1) of the Comparative Example.

As described above, the fluorine-containing liquid crystal compound ofthe present invention was demonstrated to have a low bulk viscosity, ahigh Δ∈, high photostability, and good compatibility. Thefluorine-containing liquid crystal compound of the present invention wasalso found to have sufficient Tc and Δn values sufficient for use as thecomponent of the liquid crystal composition.

As demonstrated above, use of such compound of the present invention inthe liquid crystal composition enables production of a compositionsimultaneously enjoying a high dielectric anisotropy and a low bulkviscosity.

1. A liquid crystal compound represented by the following formula (1):R¹-(A¹)_(a)-Z¹-(A²)_(b)-Z²-(A⁷)_(e)-Z⁵-A³-CF═CFCF₂O-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²  (1)wherein R¹ and R² independently represent hydrogen atom, a halogen atom,—CN, —NCS, —SF₅, or an alkyl group containing 1 to 18 carbon atoms,wherein at least one hydrogen atom in the group is optionallysubstituted with fluorine atom, at least one —CH₂— in the group isoptionally substituted with ethereal oxygen atom or thioethereal sulfuratom, and at least one —CH₂CH₂— in the group is optionally substitutedwith —CH═CH— or —C≡C—, A¹, A², A³, A⁴, A⁵, A⁶ and A⁷ independentlyrepresent trans-1,4-cyclohexylene group, 1,4-cyclohexenylene group,1,3-cyclobutylene group, 1,2-cyclopropylene group, naphthalene-2,6-diylgroup, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group,decahydronaphthalene-2,6-diyl group, or 1,4-phenylene group, wherein atleast one hydrogen atom in the group is optionally substituted with ahalogen atom, one or two ═CH— in the group is optionally substitutedwith nitrogen atom, and one or two —CH₂— in the group is optionallysubstituted with ethereal oxygen atom or thioethereal sulfur atom, Z¹,Z², Z³, Z⁴, and Z⁵ independently represent single bond, an alkylenegroup containing 1 to 4 carbon atoms wherein at least one hydrogen atomin the group is optionally substituted with fluorine atom, and at leastone —CH₂— in the group is optionally substituted with ethereal oxygenatom or thioethereal sulfur atom, and at least one —CH₂CH₂— in the groupis optionally substituted with —CH═CH— or —C≡C—, and a, b, c, d, and eindependently represent 0 or 1 with the proviso that 0≦a+b+c+d+e≦3.
 2. Aliquid crystal compound according to claim 1 wherein the liquid crystalcompound represented by the formula (1) is the compound represented bythe following formula (1-0):R¹-(A¹)_(a)-Z¹-(A²)_(b)-Z²-A³-CF═CFCF₂O-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²  (1-0)wherein R¹ and R² independently represent hydrogen atom, a halogen atom,—CN, —NCS, —SF₅, or an alkyl group containing 1 to 18 carbon atoms,wherein at least one hydrogen atom in the group is optionallysubstituted with fluorine atom, at least one —CH₂— in the group isoptionally substituted with ethereal oxygen atom or thioethereal sulfuratom, and at least one —CH₂CH₂— in the group is optionally substitutedwith —CH═CH— or —C≡C—, A¹, A², A³, A⁴, A⁵ and A⁶ independently representtrans-1,4-cyclohexylene group, 1,4-cyclohexenylene group,1,3-cyclobutylene group, 1,2-cyclopropylene group, naphthalene-2,6-diylgroup, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group,decahydronaphthalene-2,6-diyl group, or 1,4-phenylene group, wherein atleast one hydrogen atom in the group is optionally substituted with ahalogen atom, one or two ═CH— in the group is optionally substitutedwith nitrogen atom, and one or two —CH₂— in the group is optionallysubstituted with ethereal oxygen atom or thioethereal sulfur atom, Z¹,Z², Z³, and Z⁴ independently represent single bond, an alkylene groupcontaining 1 to 4 carbon atoms wherein at least one hydrogen atom in thegroup is optionally substituted with fluorine atom, at least one —CH₂—in the group is optionally substituted with ethereal oxygen atom orthioethereal sulfur atom, and at least one —CH₂CH₂— in the group isoptionally substituted with —CH═CH— or —C≡C—, and a, b, c, and dindependently represent 0 or 1 with the proviso that 0≦a+b+c+d ≦3.
 3. Aliquid crystal compound according to claim 2 wherein the liquid crystalcompound represented by the formula (1-0) is the compound represented bythe following formula (1-1):R¹¹-(A¹¹)_(a)-Z¹¹-(A²¹)_(b)-Z²¹-A³¹-CF═CFCF₂O-A⁴¹-Z³¹-(A⁵¹)_(c)-Z⁴¹-(A⁶¹)_(d)-R²¹  (1-1wherein R¹¹ and R²¹ independently represent hydrogen atom, fluorineatom, —SF₅, or an alkyl group containing 1 to 18 carbon atoms, whereinat least one hydrogen atom in the group is optionally substituted withfluorine atom, at least one —CH₂— in the group is optionally substitutedwith ethereal oxygen atom or thioethereal sulfur atom, and at least one—CH₂CH₂— in the group is optionally substituted with —CH═CH—, A¹¹, A²¹,A³¹, A⁴¹, A⁵¹, and A⁶¹ independently represent trans-1,4-cyclohexylenegroup or 1,4-phenylene group, wherein at least one hydrogen atom in thegroup is optionally substituted with a halogen atom, one or two ═CH— inthe group is optionally substituted with nitrogen atom, and one or two—CH₂— in the group is optionally substituted with ethereal oxygen atomor thioethereal sulfur atom, Z¹¹, Z²¹, Z³¹, and Z⁴¹ independentlyrepresent single bond, an alkylene group containing 1 to 4 carbon atomswherein at least one hydrogen atom in the group is optionallysubstituted with fluorine atom, and at least one —CH₂— in the group isoptionally substituted with ethereal oxygen atom, and a, b, c, and d areas defined above.
 4. A liquid crystal compound according to claim 2wherein the liquid crystal compound represented by the formula (1-0) isthe compound represented by the following formula (1-2):R¹²-(A¹²)_(a)-Z¹²-(A²²)_(b)-Z²²-A³²-CF═CFCF₂O-A⁴²-Z³²-(A⁵²)_(c)-Z⁴²-(A⁶²)_(d)-R²²  (1-2)wherein R¹² represents hydrogen atom or an alkyl group containing 1 to10 carbon atoms, wherein at least one hydrogen atom in the group isoptionally substituted with fluorine atom, and at least one —CH₂— in thegroup is optionally substituted with ethereal oxygen atom, R²²represents hydrogen atom, fluorine atom, —SF₅, or an alkyl groupcontaining 1 to 18 carbon atoms, wherein at least one hydrogen atom inthe group is optionally substituted with fluorine atom, and at least one—CH₂— in the group is optionally substituted with ethereal oxygen atom,A¹², A²², A³², A⁴², A⁵² and A⁶² independently representtrans-1,4-cyclohexylene group, 1,4-phenylene group, or 1,4-phenylenegroup wherein one or two hydrogen atoms in the group is optionallysubstituted with fluorine atom, Z¹², Z²², Z³² and Z⁴² independentlyrepresent single bond or an alkylene group containing 1 to 4 carbonatoms, and a, b, c, and d are as defined above.
 5. A method forproducing a liquid crystal compound according to claim 1, comprising thestep of reacting the compound represented by the following formula (2):CF₂═CFCF₂O-A⁴-Z³-(A⁵)_(c)-Z⁴-(A⁶)_(d)-R²  (2) with the compoundrepresented by the following formula (3):R¹-(A¹)_(a)-Z¹-(A²)_(b)-Z²-(A⁷)_(e)-Z⁵-A³-M  (3), wherein R¹, R²,A¹, A²,A³, A⁴, A⁵, A⁶, A⁷, Z¹, Z², Z³, Z⁴, Z⁵a, b, c, d, and e are as definedin claim 1; and M is a metal atom or a group containing a metal atom. 6.A liquid crystal composition containing a liquid crystal compound ofclaim
 1. 7. A liquid crystal composition containing a liquid crystalcompound of claim
 2. 8. A liquid crystal composition containing a liquidcrystal compound of claim
 3. 9. A liquid crystal composition containinga liquid crystal compound of claim
 4. 10. A liquid crystalelectrooptical element having the liquid crystal composition of claim 6introduced between two substrates each having an electrode providedthereon.
 11. A liquid crystal electrooptical element having the liquidcrystal composition of claim 7 introduced between two substrates eachhaving an electrode provided thereon.
 12. A liquid crystalelectrooptical element having the liquid crystal composition of claim 8introduced between two substrates each having an electrode providedthereon.
 13. A liquid crystal electrooptical element having the liquidcrystal composition of claim 9 introduced between two substrates eachhaving an electrode provided thereon.
 14. A liquid crystal compoundaccording to claim 1, which has a positive Δ∈ value.
 15. A liquidcrystal compound according to claim 14, which has a Δ∈ value of at least8.
 16. A liquid crystal compound according to claim 14, which has a Δ∈value of at 8 to 22.